Documentation/hwmon/f71882fg

   1 Kernel driver f71882fg
   2 ======================
   3
   4 Supported chips:
   5   * Fintek F71808E
   6     Prefix: 'f71808e'
   7     Addresses scanned: none, address read from Super I/O config space
   8     Datasheet: Not public
   9   * Fintek F71808A
  10     Prefix: 'f71808a'
  11     Addresses scanned: none, address read from Super I/O config space
  12     Datasheet: Not public
  13   * Fintek F71858FG
  14     Prefix: 'f71858fg'
  15     Addresses scanned: none, address read from Super I/O config space
  16     Datasheet: Available from the Fintek website
  17   * Fintek F71862FG and F71863FG
  18     Prefix: 'f71862fg'
  19     Addresses scanned: none, address read from Super I/O config space
  20     Datasheet: Available from the Fintek website
  21   * Fintek F71869F and F71869E
  22     Prefix: 'f71869'
  23     Addresses scanned: none, address read from Super I/O config space
  24     Datasheet: Available from the Fintek website
  25   * Fintek F71869A
  26     Prefix: 'f71869a'
  27     Addresses scanned: none, address read from Super I/O config space
  28     Datasheet: Not public
  29   * Fintek F71882FG and F71883FG
  30     Prefix: 'f71882fg'
  31     Addresses scanned: none, address read from Super I/O config space
  32     Datasheet: Available from the Fintek website
  33   * Fintek F71889FG
  34     Prefix: 'f71889fg'
  35     Addresses scanned: none, address read from Super I/O config space
  36     Datasheet: Available from the Fintek website
  37   * Fintek F71889ED
  38     Prefix: 'f71889ed'
  39     Addresses scanned: none, address read from Super I/O config space
  40     Datasheet: Should become available on the Fintek website soon
  41   * Fintek F71889A
  42     Prefix: 'f71889a'
  43     Addresses scanned: none, address read from Super I/O config space
  44     Datasheet: Should become available on the Fintek website soon
  45   * Fintek F8000
  46     Prefix: 'f8000'
  47     Addresses scanned: none, address read from Super I/O config space
  48     Datasheet: Not public
  49   * Fintek F81801U
  50     Prefix: 'f71889fg'
  51     Addresses scanned: none, address read from Super I/O config space
  52     Datasheet: Not public
  53     Note: This is the 64-pin variant of the F71889FG, they have the
  54           same device ID and are fully compatible as far as hardware
  55           monitoring is concerned.
  56   * Fintek F81865F
  57     Prefix: 'f81865f'
  58     Addresses scanned: none, address read from Super I/O config space
  59     Datasheet: Available from the Fintek website
  60
  61 Author: Hans de Goede <hdegoede@redhat.com>
  62
  63
  64 Description
  65 -----------
  66
  67 Fintek F718xx/F8000 Super I/O chips include complete hardware monitoring
  68 capabilities. They can monitor up to 9 voltages, 4 fans and 3 temperature
  69 sensors.
  70
  71 These chips also have fan controlling features, using either DC or PWM, in
  72 three different modes (one manual, two automatic).
  73
  74 The driver assumes that no more than one chip is present, which seems
  75 reasonable.
  76
  77
  78 Monitoring
  79 ----------
  80
  81 The Voltage, Fan and Temperature Monitoring uses the standard sysfs
  82 interface as documented in sysfs-interface, without any exceptions.
  83
  84
  85 Fan Control
  86 -----------
  87
  88 Both PWM (pulse-width modulation) and DC fan speed control methods are
  89 supported. The right one to use depends on external circuitry on the
  90 motherboard, so the driver assumes that the BIOS set the method
  91 properly.
  92
  93 Note that the lowest numbered temperature zone trip point corresponds to
  94 to the border between the highest and one but highest temperature zones, and
  95 vica versa. So the temperature zone trip points 1-4 (or 1-2) go from high temp
  96 to low temp! This is how things are implemented in the IC, and the driver
  97 mimicks this.
  98
  99 There are 2 modes to specify the speed of the fan, PWM duty cycle (or DC
 100 voltage) mode, where 0-100% duty cycle (0-100% of 12V) is specified. And RPM
 101 mode where the actual RPM of the fan (as measured) is controlled and the speed
 102 gets specified as 0-100% of the fan#_full_speed file.
 103
 104 Since both modes work in a 0-100% (mapped to 0-255) scale, there isn't a
 105 whole lot of a difference when modifying fan control settings. The only
 106 important difference is that in RPM mode the 0-100% controls the fan speed
 107 between 0-100% of fan#_full_speed. It is assumed that if the BIOS programs
 108 RPM mode, it will also set fan#_full_speed properly, if it does not then
 109 fan control will not work properly, unless you set a sane fan#_full_speed
 110 value yourself.
 111
 112 Switching between these modes requires re-initializing a whole bunch of
 113 registers, so the mode which the BIOS has set is kept. The mode is
 114 printed when loading the driver.
 115
 116 Three different fan control modes are supported; the mode number is written
 117 to the pwm#_enable file. Note that not all modes are supported on all
 118 chips, and some modes may only be available in RPM / PWM mode.
 119 Writing an unsupported mode will result in an invalid parameter error.
 120
 121 * 1: Manual mode
 122   You ask for a specific PWM duty cycle / DC voltage or a specific % of
 123   fan#_full_speed by writing to the pwm# file. This mode is only
 124   available on the F71858FG / F8000 if the fan channel is in RPM mode.
 125
 126 * 2: Normal auto mode
 127   You can define a number of temperature/fan speed trip points, which % the
 128   fan should run at at this temp and which temp a fan should follow using the
 129   standard sysfs interface. The number and type of trip points is chip
 130   depended, see which files are available in sysfs.
 131   Fan/PWM channel 3 of the F8000 is always in this mode!
 132
 133 * 3: Thermostat mode (Only available on the F8000 when in duty cycle mode)
 134   The fan speed is regulated to keep the temp the fan is mapped to between
 135   temp#_auto_point2_temp and temp#_auto_point3_temp.
 136
 137 All of the automatic modes require that pwm1 corresponds to fan1, pwm2 to
 138 fan2 and pwm3 to fan3.